Ratchet driven tuning means



Y 1765- 1948- o. E. WAGENKNECHT RATCHET DRIVEN TUNING MEANSOriginaIFiled Sept. 27, 1943 FIG .5

FIG.4

INVENTOR OTTO E. WAGENKNEGHT Qzwpr. fir i: H S ATTORNEY stented Feb. ii,1948 RATCHET DRIVEN TUNING MEANS Otto E. Wagenlmecht, Chicago, Ill.,assignor to Zenith Radio Corporation, a corporation of Illinois Originalapplication September 2'1, 1943, Serial No. 503.878. Divided and thisapplication December 29, 1944, Serial No. 570,281

12 Claims. (01. 192-142) This invention relates to improved means forpositioning an adjustable or variable element and, in particular, toimproved tuning means for radio apparatus.

The present application is a division of my copending application SerialNo. 503,878, filed September 27, 1943, now abandoned, and assigned tothe same assignee as the present application.

It is desirable to be able to tune radio apparatus sequentially orselectively to predetermined radio frequencies in addition to being ableto tune such apparatus continuously over a range of frequenciesincluding such predetermined frequencies. This is especially so when theradio apparatus is mounted in an automobile wherein a footswitch of thetype shown in the McDonald Patent 2,216,671 is operable by the driver ofthe automobile for tuning the apparatus sequentially when his attentionis needed elsewhere for careful driving. The occupants of theautomobile, other than the driver, and also the driver when hisattention is not needed elsewhere, will find it more satisfactory totune the apparatus selectively to a predetermined frequency, in whichcase the apparatus is not on most occasions tuned to other stationsefore the one selected is tuned. On other occasions, particularly whenthe automobile is Very distant from the broadcast station to which theautomobile radio apparatus was pretuned, it is more desirable to tune instations near the vicinity of the automobile at that time, and in suchcase the radio apparatus is preferably tuned continuously over astandard broadcast band.

It is therefore an object of the present invention to mount a completeradio receiver in an automobile and to" provide means for manuallytuning the receiver continuously over a standard broadcast band, and forsequentially tuning the receiver by a footswitch operated by the driverof the automobile, and to provide means on the dashboard or otherconvenient part of the automobile for selecting a signal from any one ofa plurality of broadcast stations without performing sequential tuningoperations such as is necessary in tuning by the use of said footswitch.

A further object of the present invention is to provide means forselectively tuning a radio receiver of the type having an electromagnetfor positioning a tuning element with respect to preset stops.

The features of the present invention, which are believed to be novel,are set forth with particularity in the appended claims. This inventionitself, both as to its organization and man- 2 ner of operation,together with further objects and advantages thereof, may best beunderstood by reference to the following description taken in connectionwith the accompanying drawing in which:

Fig. 1 is a schematic diagram of a circuit and certain associated partsespecially suitable for use with my invention and incorporating thepresent invention,

Figs. 2 and 5 are detailed views of certain parts of the apparatusillustrated in Fig. 1, and

Figs. 3 and 4 illustrate a modified form of certain portions of theapparatus shown in Fig. 1.

By the term sequential tuning in this specification it is understoodthat reference is made to stepby-step tuning of radio apparatus tofrequencies in a predetermined sequence.

By the term selective tuning in the specification it is understood thatreference is made to tuning radio apparatus to predetermined frequenciesselectively in accordance with the particular wish of the operator.

Also, by the term continuous tuning in the specification it isunderstood that reference is made to tuning radio apparatus continuouslythrough the entire range or a fractional part of a range of frequenciesin, for example, a standard broadcast band.

In Fig. 1, radio apparatus, including tuning coils i and 2, is tuned bymeans of a turret tuner of the type shown and claimed in United StatesLetters Patent No. 2,310,720, issued February 9, 1943, to Clarence W.Wandrey and assigned to the same assignee as the present application.The turret tuner may be adjusted manually by turning knob 3 located onthe header plate of an automobile as shown in the parent application ofwhich this is a division, or the knob 3 may be located on otheraccessible portions of the automobile. As will be shown presently, theknob 3 is operable to tune the associated radio apparatus continuouslyor to produce "continuous tuning of the type mentioned above.Alternatively, the associated receiving apparatus is tuned sequentiallyto one of a plurality of frequencies by sequential operation of afootswitch 4 controlled by the driver of the automobile, or tunedselectively and nonsequentially by actuating one of a series of switches5, 6, I, 8, 9 and I0 located at some convenient place in the automobile.That is, the arrangement illustrated in Fig. 1 tunes the radioapparatus, of which tuning inductances l and 2 are a part, either uponactuation of the manual tuning knob 3, the footswitch 4 or any one ofthe selecting switches 5 to ID.

The inductauces of coils I and 2 determine the frequency of the receivedsignal and these inductances are varied respectively, by adjusting theposition of members II and I2 of relatively high permeability withrespect to coils I and 2. Only two tuning inductance coils are shown inFig. 1. for simplicity, but it should be understood that more than twoand preferably three or four of such coils are tuned simultaneously bypositioning relatively high permeability members similar to members IIand I2 with respect to inductance coils which are connected in the radioreceiving apparatus. The tuning members or control members, such asmembers II and I2, are carried on a movable carriage I3, which issecured upon a rod I4 connected to a movable solenoid core I 5. The rodI4 has its forward end I8 bent so as to cooperate with one of aplurality of stops or abutments I1 of the assembly I8; and these stepsI1 are adjustably held in a turret member I8 by cooperating screwthreads on stops I1 and turret member I8 (Fig. 2).

The turret member I8 is secured upon a rotatable shaft I 9 which carriesa ratchet wheel 20 engaged with pawl 2I so as to rotate the shaft I9 onestep or one-sixth of a revolution for each reciprocation of the pawl 2I. The pawl 2i is pivotally mounted on an arm 22 which swings about theshaft I9 and is pivotally and slidably connected to one arm of a bellcrank 23 having its other arm pivotally and slidably connected to alever member 24, the latter being pivoted on a fixed pivot pin 25. Thelever member 24 extends from its pivot pin 2 6 and has a slot 21 toaccommodate a pin 28 secured upon the rod I4. The upper end of the lever24 is preferably positioned so as to be visible and cooperates with ascale 29 having suitable graduations thereon whereby a suitableindication of the position of rod I4 and tuning members II and I2 isobtained.

With the apparatus thus far described in Fig. 1, it is clear that whenrod l4 moves to the left in the direction of its axis, the bell crank 23rotates behind an adjacent tooth on the ratchet wheel 20, and that whenthe rod I4 returns to the right the ratchet wheel 20 is rotated onesixthof a revolution to a position where an adjacent stop I1 on turret I8limits further movement of the rod I4 and inductance tuning members IIand I2 carried thereon. The manner in which the solenoid core I andassociated rod I4 are actuated by electromagnetic means is describedhereinafter.

Upon turret shaft I9 is mounted homing device 30 having a rotatable andgrounded electrical contact making member 3i which rotates when and asturret shaft I9 rotates for effecting suitable electrical switching. Itis clear from the drawings that contact making member 3I is attached toturret shaft I9 which has secured thereon turret member I8. It isobvious therefore that contact making member 3I is firmly attached toturret member l8 through shaft I9 and for purposes of explanation it maybe said that contact making member 3i is carried by turret member IBinasmuch as member 3| is firmly connected with and always moves withturret member I8. Homing device 30 has six equally spaced fixed contacts32, 33, 34, 35, 36 and 31 arranged so that when the turret I8 is in oneof its six positions corresponding to the position wherein rodI4'engages one of the stop members I1, the contact making member 3Iengages one of the fixed contacts 32 to 31 on the homing device.

Each one of the contact members 32, 33, 34, 35,

3| and I1 is connected to a respective normally closed stationarycontact on a respective one of the station selecting switches 5, O, 1,and II; and the other contacts 3|, 3|, 4|, H, 42 and 43, which aremovable, are each connected to a common low resistance conductor 44.Each one of the selecting switches I to II has a normally open fixedcontact connected to corresponding contacts on the other selectingswitches by means of low resistance connection 4| which is alsoconnected to one terminal of a voltage source 4i. The other terminal ofvoltage source 4| is connected to a terminal of actuating solenoid 41which has its other terminal connected to ground through anautomatically operated position responsive switch 4|.

Thus, when one of the selecting switch contact members 3| to 43, forexample-switch contact member 33 is moved from its normally closedposition to the position where it engages contact 49, current flows fromone terminal of voltage source 46 through solenoid actuating winding 41,switch 4|, ground, arm II, contact 31, the normally closed contact onelectric switch II, movable contact 43, conductor 44, movable contact38, and the normally open contact 4! on selecting switch 5 back to theother terminal of voltage source 4|.

When solenoid 41 is energized, for example, by thus producing a currentflow through the normally open contact 43 on switch 5 in the mannerdescribed above, solenoid core 41 and rod I4 are moved to the left inFig. 1 to a position where solenoid extension 5|, of insulatingmaterial, engages and actuates the switch 4| from circuit closingposition to circuit opening position and thus opens the circuit tosolenoid winding 41, and in so doing allows solenoid core I5 to returnto its furthermost position to the right under the influence of tensionspring 5|, after pawl 2| has turned the turret I| an angular distancecorresponding to the distance between adjacent stops l1.

In the return movement of rod I4 to the right, in order to be sure thatthe rod I4 moves sufficiently far to the right to move the ratchet wheel20 one-sixth of a revolution before the solenoid is energized againthrough switch 4|, time delay means 52, illustrated as a fluid dashpot,are connected to the resilient movable contact of switch 48, which timedelay means delays reclosing of the switch 43 after it has been openedby member 50. It is clear that the time delay means 52 may take otherforms than the liquid dashpot shown in Fig. 1, and, in fact, the switch4| may have time delay means incorporated therein as shown in Figs. 3and 4.

The liquid dashpot as illustrated has a movable plston 53 with anorifice 54 for controlling the speed of piston travel to the right inFig. 1. A second and larger piston orifice 55 is opened by conventionalmeans (not shown) only when the piston moves to the left in Fig. 1 incooperating cylinder 5| so that the piston 53 may move faster to theleft than it moves to the right with the same forces applied thereto.

Insummary, when it is desired to select one of a plurality of broadcaststations determined by the relative position of a particular stop memberI1 in turret member I|, one of the switches I to I 0, corresponding tothat particular stop member, is actuated so as to energize solenoid 41.When solenoid 41 is energized due to current flowing from voltage source46, solenoid rod I4 is moved to the left against the action of tensionspring II, and pin 28 on rod l4 engages lever 24 which pivots around itspivot pin 28 so as to rotate the bell crank 23 counterclockwise aroundits pivot member 25. When and as hell crank 23 moves thuscounterclockwise, arm 22 pivotally mounted on shaft l9 and havingpivotally mounted thereon pawl 2| rotates counterclockwise about itssupporting shaft IS a distance somewhat greater than one-sixth of arevolution so as to allow pawl 2| to drop behind and engage an adjacenttooth on ratchet wheel 20. When solenoid 41 is deenergized due to theopening of switch 48, tension spring 5| causes clockwise movement oflever arm 24 and causes the turret 8 to be moved an angular distancecorresponding to the angular distance between teeth on ratchet 20, whichdistance corresponds to the angular distance between stops |1,

Such action continually repeats itself until wheel 28 and stops l1,together with arm 3|, are turned to the fixed contact connected to thatone of switches 5 to ID which is actuated, and at that fixed contact,the circuit, through the switches 5 to In being broken by its actuation,the repeated action stops and the desired station is selected.

Stops H are adjustably mounted in turret member l8 and the relativeposition of each particular stop 11 in turret member |8 determines thedistance tuning members II and i2 project respectively within inductancecoils I and 2 after the turret member I8 is rotated around to a position where that particular stop limits movement of rod it.

It is thus clear that when one of the switches d to it! is actuated, theturret member i8 is rotated, due to current flow through solenoid 41,which current also flows intermittently through the normally opencontact of that particular switch and the normally closed contact of theother switches until the rotating contact 3t of homing device 30 engagesone of the contacts 32 to 3? corresponding to the switch which isactuted. When the rotating contact 3| engages the stationary contactcorresponding to the particular switch actuated, then current flow tothe solenoid 41 is interrupted. That is, when switch 5 is actuated,turret member I8 is rotated until rotating contact 3| engages contact32, and when switch 6 is actuated, contact 3| stops at contact 33. etc.

It is also clear that when footswitch 4, which is connected in a seriescircuit with source 46 and solenoid 41, is closed, solenoid 41 draws thecore I5 to the left and causes the arm 22 to rotate one stepcorresponding to the angular distance between stop members.

Therefore, in order to tune the receiver by actuating the footswitch 4,it is necessary that the switch 4 be sequentially closed and openeduntil a particular stop |1, corresponding to a desired station, limitsmovement of rod l4, whereas, when the receiver is tuned by actuating oneof the switches 5 to In, the particular switch memher-for example,switch member 38-is moved to make contact with stationary contact 48,and the receiver is tuned without further actuation of switch member 38.

Figs. 3 and 4 show, respectively, the circuit closing and circuitopening positions of a switch which may be substituted for the switch 48.in Fig. 1 and having suitable time delay means in corporated therein.This substitute switch comprises the relatively fixed contact member 51and the relatively movable contact member 58 which is coupled to thefree end of movable memher 58, having spring supports 88 and 8|. througha substantially U-shaped spring member 82 for producing a suitable timedelay. The other con- Relative movement between the free end of.

contact member 51 and movable contact member 58 is produced when and asthe member of insulating material on solenoid core M (Fig, 1) moves tothe left after engaging the free end of member 68 which pivots about itsclamped end.

When, as in Fig. 4, member 50 does not engage the free end of pivotablemember 88, contact members 51 and 58, comprising switch 48, are incircuit closing position. When, as in Fig. 3, member 50 has engagedmember 68 and has moved it to the left, contact members 58 and 63 are incircuit opening position. When member 58 moves to the right from itsposition shown in Fig. 3, it may move a. relatively large distancebefore contacts 51 and 58 assume circuit closing position because of theresilient connection 59, and thereby a time delay is produced because ittakes time for pin 50 to move.

The relatively large distance which member 58 attached to solenoid coreI 5 (Fig. 1) moves without effecting a closing of switch 48 comprisingcontacts 51 and 58 is sufllcient to allow pawl 2| to move ratchet wheel20 an angular distance substantially equal to the angular distancebetween adjacent stops i1. Then, after the member 50 moves further thansaid large distance, switch 48 closes and thus allows deenergization ofsolenoid 41.

With a receiver including the delayed action switches of Figs. 3 and 4in the arrangement of Fig. 1, in tuning the receiver by actuating one ofthe switches 5 to lit-for example, switch 5 movable contact member 38need only engage normally open contact 49 for a relatively short timewithin which time contact member 3| is rotated rapidly to contact 32.That is, it is not necessary to operate movable member 38 recurrently asis the case when tuning with the footswitch 4. As a matter of fact, whenthe time delay means, such as the dashpot in Fig. 1 or switch shown inFigs. 2 and 3, is properly adjusted, the turret member I8 is rotated oneturn within a time oi. the order of one second when one of the switches5 to II! is actuated.-

The receiver may be also tuned manually by turning tuning means 3.Referring to Fig. 1, tuning means 3 is arranged to adjust the positionof at least one of the stop members H in the turret member l8. For thatpurpose, tuning means or knob 3 is coupled to gear 69 through shaft 10.Gear 69 is arranged to engage at least one of the stop gears 1| which,as shown in Fig. 2, is threaded in stop member i8 and is confined withina hollow portion of turret member 8 between walls 12 and 13.Conventional means, not shown, is provided to prevent rotation of stopI1 within member l8 when gear 1| is turned. When knob 3 is turnedmanually, the stop I1 is turned in or out of turret member l8 in adirection depending upon the direction of rotation of knob 3; and rod Hwhich is pressed against stop I! by tension spring follows the movementof stop member H. The position of rod i4, as explained previously,determines the inductance of coils l and 2 and, hence, the tuning of thereceiver.

In addition to serving as a manual tuning means, the knob 3 may beturned to adjust the position of the other stop members I! in turret l8so that the stop members I! may be in suitable position for tuning whenthe footswitch 4 or one of switches 5 to M is actuated.

The switches 5 to ill shown in Fig. 1 may be of the pushbutton type and,as shown in Fig. 5, may be mounted on header enclosure member 14, or onthe instrument panel or other convenient place by fastening means-forexample, rivets 15. For simplicity, only one switch 5, having normallyclosed fixed contact member ll, relatively movable contact member 38 andnormally open fixed contact member 48, is shown in Fig. 5, and it shouldbe understood that the other switches 8 to ID are of similarconstruction and are spaced in side-by-side relationship to switch 5.

In Fig. 5, the adjacent fixed ends of contact members 38 and 48 areseparated by insulation 18 and are fastened to insulating support 18 byfastening means-for example, rivet 88-which is insulated from thecontact members 38 and 49 and also serves to clamp one end of actuatingmember 8!. The bottom contact member 11 is mounted on insulation 82 byfastening means similar to screws (not shown), and the insulation 82 isfastened to support 83 by fastening means-for example, screws 84.Supporting members 19 and 84 are held together in spaced relationship bymeans of plate 85 and fastening means 88.

Pushbutton 81, shown in its further-most left position in Fig. 5, has anextension 88 with a cam surface arranged to engage spring actuatedmember 89, which abuts the relatively movable spring contact 38 so as tomove it from a position where contact member 38 engages fixed contactmember IT to a position where contact member 38 engages member 49 whenpushbutton 81 is pressed to the right against the action of compressionspring 98 on extension 8 l, and which spring is disposed between support83 and the pushbutton extension 92. Pushbutton extensions 9|, 92 and 93,movable in cooperating apertures in support 83, and extension 84,movable in a coopcrating aperture in support 18, serve as guide membersfor movement of the pushbutton 81. Pushbutton extension 83 projectingthrough support 83 is bent so that it cannot be withdrawn throughsupport 83 whereby the extension limits the movement of pushbutton 81produced by compression spring 98.

While the particular embodiments of the present invention have beenshown and described, it will be obvious to those skilled in the art thatchanges and modifications may be made without departing from thisinvention in its broader aspects, and, therefore, the aim in theappended claims is to cover all such changes and modifications as fallwithin the true spirit and scope of this invention.

I claim:

1. In a system for positioning a control member, a movable controlmember, a series of stops movable as a unit, means normally holding thecontrol member in engagement with one of the stops, an electromagnet,movable actuating means operated by energization of said electromagnetfor disengaging the control member from said one stop and for moving thestop member, a switch actuated by the movement of the stop members in aseries circuit with said electromagnet, and switch means operated by themovement of said movable actuating means for recurrently energizing theelectromagnet through said first switch to cause said control member toengage a predetermined stop.

2. In a tuning system for a radio receiver, a movable tuning member, acontrol member attached to said tuning member, a series of stops movableas a unit, means normally holding the control member in engagement withone of the stops, an electromagnet, movable actuating means operated byenergization of said electromagnet for disengaging the control memberfrom said stop member and for moving the control member and stop member,switchin means actuated in response to movement of the stop members, aseries of control switches, a voltage source, an electrical circuitincluding the voltage source for energizing the electromagnet throughthe switching means and the series of control switches, and delay meansfor recurrently closing said electrical circuit to cause said controlmember to engage a predetermined stop.

3. Selective control apparatus for the control of electrical equipment,movable control means, a series of movable stop members, means normallyholding the control means in engagement with one of the stop members, aswitch actuated in response to movement of the stop members, meansincluding an electrical circuit energized through said switch for movingthe control means and stop members, and a switch actuated in response tomovement of the control means for interrupting said electrical circuitto cause said control member to engage a predetermined stop member.

4. In apparatus for the control of electrical equipment, a movablecontrol member, a series of stop members, means normally holding thecontrol member in engagement with one of the stop members, a switchactuated in response to movement of the stop members, means including anelectrical circuit through said switch for disengaging the controlmember from engagement with the stop and for moving the stops, and aswitch actuated in response to the movement of the control member forinterrupting said electrical circuit to cause said control member toengage a predetermined stop member.

5. Selective tuning apparatus for the control of electrical equipmentcomprising a movable controlling member, an electromagnet for movingsaid member in one direction, resilient means tending to move saidmember in the opposite direction, a stop assembly comprising spacedstops, means on said movable controlling member for cooperation withsaid stop assembly, means to bring about cooperation of said stops withsaid member in a predetermined order, a switch actuated in response tomovement of the stop assembly, an electrical circuit including saidswitch for controlling the energization of said electromagnet throughsaid switch, and means actuated after energization of said electromagnetfor interrupting said electrical circuit to cause said controllingmember to assume a predetermined position.

6. A tuner for a radio receiver comprising a movable tuning device, anelectromagnet for moving said tuning device in one direction, resillentmeans tending to move said device in the opposite direction, a movablestop assembly comprising spaced stops, means successively to positionsaid stops for cooperation with said tuning device, said last namedmeans operating in timed relationship with energization of saidelectromagnet, switching means actuated in response to movement of saidstop assembly, an electrical circuit including said switching means forenergizing said electromagnet, and a series of switches in parallelconnected to said switching means for energizing said electromagnetthrough said switching means.

'7. In apparatus for the control of electrical equipment, a movablecontrol member, a series of stop members, means normally holding thecontrol member in engagement with one of the a stop members, a switchactuated in response to movement of the stop members, means operated byan electrical current flowing through said switch for disengaging themovable control member from engagement with one of the stop members andfor moving the stop members, a normally closed switch actuated inresponse to movement of the control member for interrupting saidelectrical circuit, and delay means for maintaining the last mentionedswitch in circuit interrupting position a predetermned period of timeafter movement of said control member to cause said control member toengagea predetermined stop.

8. In a system for tuning radio apparatus, a tuning member, a series offrequency determining members rotatable as a unit and operativelyassociated with said tuning member to position said tuning member, arotatable indexing member, step by step means to rotate said indexingmember and to rotate said series of frequency determining members,solenoid means to move the step by step means in one direction, springmeans to move said step by step means in the opposite direction, switchmeans operated by the movement of the step by step means to alternatelyenergize and deenergize the solenoid means, and switching means actuatedby the rotation of the indexing member in series with the first namedswitching means to cause the member to stop at a desired index and toposition the tuning member.

9. In a system for tuning radio apparatus, a tuning member, a series offrequency determining members rotatable as a unit and operativelyassociated with said tuning member to position said tuning member, arotatable indexing member, step by step means to rotate said indexingmember and to rotate said series of stops, solenoid means to move thestep by step means in one direction, spring means to move said step bystep means in the opposite direction, switching means operated by themovement of the step by step means to alternately energize anddeenergize the solenoid means, switching means actuated by the rotationof the indexing member in series with the first named switching means tocause the indexing member to stop at the desired index, and a pluralityof switches in 10 parallel connected to the switching means actuated bythe rotation of the member to individually initiate an energizingcircuit.

10. In a system for tuning radio apparatus, a tuning member, a series offrequency determining members rotatable as a unit and operativelyassociated withsaid tuning member to position said tuning member, arotatable indexing drum, ratchet solenoid means to rotate the drum andto rotate said series of frequency determining members, switching means,a portion of which is mounted adjacent the drum and a portion carried bythe drum controlling the solenoid ratchet drive, and a second series ofswitching means connected to the first named switching means to indexthe drum and position the tuning member.

11. In an indexible positioning device, a rotatable indexing member, aplurality of stops carried by said member, an adjustable element biasedagainst one of said stops, a ratchet solenoid for moving said elementfrom said one stop and for rotating said member to move a subsequentstop into position to engage said element, a switch in circuit with saidelectromagnet for opening the circuit therethrough upon movement of saidelement away from any one of said stops, and a switching arrangementactuated by rotation of said member in series with said switch to causesaid member to stop with a desired one of said stops in engagement withsaid element.

12. In an inflexible positioning device, a rotatable indexing member, aplurality of stops carried .by said member, an adjustable elementmovable to abut against one of said stops, a spring biasing said elementagainst said one stop, an electromagnet connected with a stepby-stepratchet for moving said element against the force of said spring fromsaid one stop and for rotating in step-by-step fashion said member tomave a subsequent stop into position to engage said element against theforce of said spring, a switch in circuit with said electromagnet foropening the circuit therethrough upon REFERENCES CITED The followingreferences are of record in the file of this patent:

UNITED STATES PATENTS Name Date Lyman et al Mar. 9, 1943 Bryce July 12,1932 Pillion Sept. 10, 1929 Wandrey Feb. 9, 1943 Horlacher Nov. 25, 1930Number

